You may be asking yourself, why do i position well in yahoo and msn, but not in Google?

Well your probably getting penalized for something that you have implemented into the search engine marketing of your site. Different search engine use different algorithms and each search engine weighs different parts of a site differently.

• Google are the primary UK & US search engine, Google focuses on the sites age and link based authority and popularity, they are the industry leaders and seem to have the best system for determining the Good sites from the poor sites, spammers and aggressive optimisers.
• Yahoo! focuses more on the page content side of thing, but while still relying on a large decent link base.
• MSN is easier to manipulate, by using low-quality links, aggressive anchor text and high population of keywords, getting a higher position becomes more possible.

Tweaking a pages internal optimization is very time consuming and the effect is mostly un-noticeable once a decent standard has been set, your better off trying to research quality links that have value and are from a industry site related to you.